package com.yunkuent.sdk.utils;

/**
 *
 * LibFormula : a free Java formula library
 *
 *
 * Project Info:  http://reporting.pentaho.org/libformula/
 *
 * (C) Copyright 2006-2007, by Pentaho Corporation and Contributors.
 *
 * This library is free software; you can redistribute it and/or modify it under the terms
 * of the GNU Lesser General Public License as published by the Free Software Foundation;
 * either version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this
 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
 * in the United States and other countries.]
 *
 *
 * ------------
 * $Id: URLEncoder.java 3521 2007-10-16 10:55:14Z tmorgner $
 * ------------
 * (C) Copyright 2006-2007, by Pentaho Corporation.
 */

import java.io.UnsupportedEncodingException;

/**
 * Creation-Date: Jan 22, 2007, 4:36:38 PM
 *
 * @author Thomas Morgner
 */
public class URLEncoder {
    private URLEncoder() {
    }

    private static final String[] hex = {"%00", "%01", "%02", "%03", "%04", "%05", "%06", "%07", "%08", "%09", "%0A", "%0B", "%0C", "%0D", "%0E", "%0F", "%10", "%11", "%12", "%13", "%14", "%15", "%16", "%17", "%18", "%19", "%1A", "%1B", "%1C", "%1D", "%1E", "%1F", "%20", "%21", "%22", "%23", "%24", "%25", "%26", "%27", "%28", "%29", "%2A", "%2B", "%2C", "%2D", "%2E", "%2F", "%30", "%31", "%32", "%33", "%34", "%35", "%36", "%37", "%38", "%39", "%3A", "%3B", "%3C", "%3D", "%3E", "%3F", "%40", "%41", "%42", "%43", "%44", "%45", "%46", "%47", "%48", "%49", "%4A", "%4B", "%4C", "%4D", "%4E", "%4F", "%50", "%51", "%52", "%53", "%54", "%55", "%56", "%57", "%58", "%59", "%5A", "%5B", "%5C", "%5D", "%5E", "%5F", "%60", "%61", "%62", "%63", "%64", "%65", "%66", "%67", "%68", "%69", "%6A", "%6B",
            "%6C", "%6D", "%6E", "%6F", "%70", "%71", "%72", "%73", "%74", "%75", "%76", "%77", "%78", "%79", "%7A", "%7B", "%7C", "%7D", "%7E", "%7F", "%80", "%81", "%82", "%83", "%84", "%85", "%86", "%87", "%88", "%89", "%8A", "%8B", "%8C", "%8D", "%8E", "%8F", "%90", "%91", "%92", "%93", "%94", "%95", "%96", "%97", "%98", "%99", "%9A", "%9B", "%9C", "%9D", "%9E", "%9F", "%A0", "%A1", "%A2", "%A3", "%A4", "%A5", "%A6", "%A7", "%A8", "%A9", "%AA", "%AB", "%AC", "%AD", "%AE", "%AF", "%B0", "%B1", "%B2", "%B3", "%B4", "%B5", "%B6", "%B7", "%B8", "%B9", "%BA", "%BB", "%BC", "%BD", "%BE", "%BF", "%C0", "%C1", "%C2", "%C3", "%C4", "%C5", "%C6", "%C7", "%C8", "%C9", "%CA", "%CB", "%CC", "%CD", "%CE", "%CF", "%D0", "%D1", "%D2", "%D3", "%D4", "%D5", "%D6", "%D7", "%D8", "%D9", "%DA", "%DB",
            "%DC", "%DD", "%DE", "%DF", "%E0", "%E1", "%E2", "%E3", "%E4", "%E5", "%E6", "%E7", "%E8", "%E9", "%EA", "%EB", "%EC", "%ED", "%EE", "%EF", "%F0", "%F1", "%F2", "%F3", "%F4", "%F5", "%F6", "%F7", "%F8", "%F9", "%FA", "%FB", "%FC", "%FD", "%FE", "%FF"};

    /**
     * Encode a string accordiNetConnectionng to RFC 1738.
     * <p/>
     * <quote> "...Only alphanumerics [0-9a-zA-Z], the special characters "$-_.+!*'()," [not including the quotes - ed], and reserved characters used for their reserved purposes may be used unencoded within a URL."</quote>
     * <p/>
     * <ul>
     * <li>
     * <p/>
     * The ASCII characters 'a' through 'z', 'A' through 'Z', and '0' through '9' remain the same.
     * <p/>
     * <li>
     * <p/>
     * The unreserved characters - _ . ! ~ * ' ( ) remain the same.
     * <p/>
     * <li>
     * <p/>
     * All other ASCII characters are converted into the 3-character string "%xy", where xy is the two-digit hexadecimal representation of the character code
     * <p/>
     * <li>
     * <p/>
     * All non-ASCII characters are encoded in two steps: first to a sequence of 2 or 3 bytes, using the UTF-8 algorithm; secondly each of these bytes is encoded as "%xx".
     * </ul>
     *
     * @param s The string to be encoded
     * @return The encoded string
     */
    public static String encodeUTF8(final String s) {
        final StringBuffer sbuf = new StringBuffer();
        final char[] sChars = s.toCharArray();
        final int len = sChars.length;
        for (int i = 0; i < len; i++) {
            final int ch = sChars[i];
            if ('A' <= ch && ch <= 'Z') { // 'A'..'Z'
                sbuf.append((char) ch);
            } else if ('a' <= ch && ch <= 'z') { // 'a'..'z'
                sbuf.append((char) ch);
            } else if ('0' <= ch && ch <= '9') { // '0'..'9'
                sbuf.append((char) ch);
            } else if (ch == '-' || ch == '_' // unreserved
                    || ch == '.' || ch == '!' || ch == '~' || ch == '*' || ch == '\'' || ch == '(' || ch == ')') {
                sbuf.append((char) ch);
            } else if (ch <= 0x007f) { // other ASCII
                sbuf.append(hex[ch]);
            } else if (ch <= 0x07FF) { // non-ASCII <= 0x7FF
                sbuf.append(hex[0xc0 | (ch >> 6)]);
                sbuf.append(hex[0x80 | (ch & 0x3F)]);
            } else { // 0x7FF < ch <= 0xFFFF
                sbuf.append(hex[0xe0 | (ch >> 12)]);
                sbuf.append(hex[0x80 | ((ch >> 6) & 0x3F)]);
                sbuf.append(hex[0x80 | (ch & 0x3F)]);
            }
        }
        return sbuf.toString();
    }

    private static String encodeBytes(final byte[] s) {
        final StringBuffer sbuf = new StringBuffer();
        final int len = s.length;
        for (int i = 0; i < len; i++) {
            final int ch = (s[i] & 0xff);
            if ('A' <= ch && ch <= 'Z') { // 'A'..'Z'
                sbuf.append((char) ch);
            } else if ('a' <= ch && ch <= 'z') { // 'a'..'z'
                sbuf.append((char) ch);
            } else if ('0' <= ch && ch <= '9') { // '0'..'9'
                sbuf.append((char) ch);
            } else if (ch == '-' || ch == '_' // unreserved
                    || ch == '.' || ch == '!' || ch == '~' || ch == '*' || ch == '\'' || ch == '(' || ch == ')') {
                sbuf.append((char) ch);
            } else { // other ASCII
                sbuf.append(hex[ch]);
            }
        }
        return sbuf.toString();
    }

    public static String encode(final String s, final String encoding) throws UnsupportedEncodingException {
        if ("utf-8".equalsIgnoreCase(encoding)) {
            return encodeUTF8(s);
        }

        return encodeBytes(s.getBytes(encoding));
    }

}